/* ── Base ── */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; }

/* ── Scroll-reveal (progressive enhancement) ── */
@media (prefers-reduced-motion: no-preference) {
  .scroll-reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1), transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
  }
  .scroll-reveal.revealed {
    opacity: 1;
    transform: translateY(0);
  }
  .reveal {
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1) 0.15s, transform 0.7s cubic-bezier(0.22, 1, 0.36, 1) 0.15s;
  }
}

/* ── Nav scroll state ── */
#nav {
  transition: background 0.35s ease, box-shadow 0.35s ease;
}
#nav.nav-scrolled {
  background: rgba(6, 14, 31, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: 0 1px 0 rgba(255,255,255,0.06);
}

/* ── Mobile menu ── */
#mobileMenu.open {
  opacity: 1;
  pointer-events: auto;
}

/* ── Utility ── */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}